Sewer wet well conduit for submerged pumps.


Senior Member
Sorry to open this up again but I guess I don't understand the problem. A sanitary sewer wet well is typically a Class 1 division 1 or 2 area per NFPA 820 depending if it is ventilated or not. I was taught and I believe it to be NEC compliant to bring the pump cables (furnished with the submersible pump) up into a junction box in conduit, splice the pump conductors to THHN/THWN in the junction box on terminal strips or wire nuts and put the seal on the conduit with the THHN/THWN going to the starter/vfd or motor service disconnect. No seal is required between the pump and the J-box as the J-box does not have any arcing equipment in it.
Why not make it really simple and stop the conduit before it exits the classified area and let the cord make the transition between the classified and non classified areas (in free air)? No seal required since the cord does not pass gases (hey, I made a funny).